In joining of biological tissue substitute components made of ceramic hydroxyapatites, which are biomaterials, machining has been difficult because a fracture (also referred to as crack) occurs in the hydroxyapatites in a melting process for the hydroxyapatites. Therefore, as a method of forming the hydroxyapatites in a component shape, molding by a die or machining has been generally adopted.
It is known that, in a machining method for combining a bone tissue and an implant material such as ceramic, which is a biomaterial, or a composite material, a texture machined surface is used for the implant material to enhance bone adhesion and, therefore, to stabilize the position of the implant material (a surgical transplant material) with respect to a bone. For example, in an artificial hip including a thighbone sub-aggregate fixedly attached in the thighbone of a patient and an acetabulum sub-aggregate fixedly placed in the acetabulum of the patient, the thighbone sub-aggregate representatively includes an artificial stem provided with a texture machined surface and the acetabulum sub-aggregate representatively includes an artificial cup provided with the texture machined surface. The texture machined surfaces are provided to facilitate proliferation of bones. However, texture machined surfaces are positioned until adhesion and fixed by plaster casts after setting. A period of several months is sometimes required until fixation.
Therefore, to realize a reduction and stabilization of a time for joining the implant material and the bone tissue, a technology for joining the implant material and the bone tissue using laser machining has been disclosed (see, for example, Patent Literature 1). A technology for realizing improvement of biocompatibility and high toughness of adhesion to a tissue has also been disclosed (see, for example, Patent Literature 2).